A Pennsylvania man was helping decorate his mother-in-law’s tombstone Monday ahead of the Easter holiday when it suddenly toppled over, pinning him underneath and killing him, a cemetery caretaker said.

The 400-pound stone fatally injured Stephen Woytack, 74, of Scranton, said Edward Kubilas, caretaker of St. Joseph’s Catholic Cemetery in the eastern Pennsylvania town of Throop, just outside of Scranton.

On Monday morning, Woytack was kneeling next to the grave marker while his wife tied a cross on the other side, Kubilas said. The stone toppled without warning in the soft spring ground.

“His wife came running to get me,” Kubilas told Reuters. “By the time I got there, he was not too good. I got half the stone off him. It must have been adrenaline.”

A police officer and ambulance arrived almost immediately and helped him wrestle the rest of the 4-foot-by-4-foot stone off Woytack, Kubilas said, but it was too late to save him.

“It’s a tragic thing,” Kubilas said. “There’s nothing you could do.”

Woytack and his wife visited the cemetery several times each year to decorate the family grave, Kubilas said.